Hydraulic operating mechanism for well pumps



Nov. 29, 1949 H. HARVEY 2,489,412

HYDRAULIC OPERATING MECHANISM FOR WELL PUMPS' Filed Sept. 10', 1946 7 Shee'ts-Sheet 1 as :4 a 3 wavroe HYDRAULIC OPERATING MECHANISM FOR WELL PUMPS '7 Sheets-Sheet 3 Filed Sept. 10,4946

94%?47/46/11/1/1/9/6Ir/41541111111156 v I H. HARVEY HYDRAULIC OPERATING MECHANIS! FOR WELL PUMPS III/ll W I- H I l al.

.57. I i 53 E 5.9-

. IN l/EN 702 By fly HTTOENEV Nov. 29, 1949 Nov. 29, 1949 H. HARVEY 2,489,412

HYDRAULIC OPERATING MECHANISM FOR WELL PUMPS Filed Sept. 10, 1946 7 Shets-Sheet 5 Will/111,

INVENTOE WWW ,H. HARVEY 2,489,412

7 Sheets-Sheet 6 HYDRAULIC OPERATING MECHANISM FOR WELL vPUMPS a w fi w 1 fl w w MF M V w v m 1 W v My, 5 a 7 w w u v w W Nov. 29, 19 19 Filed Sept. 1o. 194s H TTOENEI Nov. 29, 1949 H. HARVEY HYDRAULIC OPERATING MECHANISM FOR WELL PUMPS '7 Sheets-Sheet 7 Filed Sept. 10, 1946 w H v WEE prroezvn" the pump.

Patented Nov. 29, [949 HYDRAULIC OPERATING MECHANISM FOR WELL PULIPS Herbert Harvey, Los Angeles, Calif., assignor to Leo M. Harvey, Los Angeles, Calif.

Application September 10, 1946, Serial No. 695,912

13 Claims.

This invention has to do with a pump operating mechanism and is more specifically concerned with a mechanism of a type that can be used to advantage to operate a well pump, as for instance, an oil well pump, itbeing a general object of the present invention to provide a practical, dependable, eifective mechanism of this general character.

The operating mechanism of the present invention can be used to advantage in various situations. However, it is particularly useful for operating a well pump or the like and can be used to great advantage in operating an oil well pump where it is desired to gain a long stroke of the sucker rod which extends into the well to operate It is generally recognized that the ordinary type of mechanical well pump commonly employed is limited in use, since in deep wells the string of sucker rods becomes so long as to absorb the greater part of the motion imparted to its upper end and, in practice, it has been difilcult or impractical to move the upper end of the string of sucker rods through a long stroke such as a deep well requires.

It is a general object of the present invention to provide a pump operating mechanism which utilizes fluid pressure as an operating medium and is such that it can be readily constructed in a manner to impart a very long stroke to a string of sucker rods.

It is an object of the present invention to provide a practical and simple operating mechanism of the general character referred to which involves a constantly operating pressure generator or pump and a high pressure supply means or accumulator which is related to the pump to supply liquid thereto during the up or work stroke of the mechanism. The high pressure supply means of the present mechanism handles the necessary supply of operating liquid as the mechanismis delivering liquid to the jack cylinder to move the sucker rods and it carries a cushion of air under an initial pressure which is increased or supplemented by the delivery of liquid during the period that the jack is lowering the string of sucker rods.

It is a general object of the present invention to provide an operating mechanism of the general character hereinabove referred to which involves a jack mechanism or lift cylinder, an accumulator, and a pumping unit so combined and related through suitable connections and controls as to enable the pump unit to operate continuously and under a substantially constant stantial volume is alternately delivered to the jack and the accumulator. The liquid delivered to the jack works or is utilized to lift the string of sucker rods whereas the liquid delivered to the accumulator is'utilized to develop pressure'which acts to feed liquid to the pump when it is acting to deliver liquid to the jack.

Another object of the present invention is to provide an improved, simplified, main or working valve which combines in a single compact and practical unit the various essential fiow controls required for the handling of liquid to and from the pump unit.

Another object of the present invention is to provide an improved, simple, and efiective control means responsive to the action of the jack and controlling the operation of an operating means for the main or working valve and which is characterized by a pilot valve involving a simple,

dependable hydraulic latch which insures dependable operation of the mechanism.

A further object of the present-invention is to provide a simple, practical, efllcient means which serves to supply air to the mechanism so that air that leaks or is lost from the mechanism in the course of operation is replenished, eliminating the danger of the mechanism failing to function properly for want of the proper amount of air in the system.

Another object of the present invention is to provide a simple practical dependable means for supplying liquid to the apparatus to serve as a feed or make-up for liquid that may leak or be lost in the course of operation. The apparatus is not only adequately supplied with make-up feed but is such that any excess of liquid is efiectively removed during the normal course of operation, eliminating danger of improper operation that might result if the apparatus were overloaded with liquid.

The various objects and features of my invention will be fully understood from the following detailed description of a typical preferred form and application of the invention, throughout which description reference is made to the accompanying drawings, inwhich:

Fig. 1 is a side elevation of a typical preferred form of the invention, showing the general relationship of the essential elements. Fig. 2 is a plan view of the machine shown in Fig. 1, being a view taken as indicated by line 2-2 on'Fig. 1. Fig. 3 is an end view of the structure taken as indicated by line 33 on Fig. '1. Fig. 4 is 9. diagrammatic view illustrating the general system load while liquid under pressure and in subinvolved in the apparatus. Fig. 5 is an enlarged 3 detailed sectional view of the main or working valve, being a view taken as indicated by line 5-5 on Fig. 2, and showing the valve positioned to admit liquid from the pump to the jack so the jack is operated upwardly. Fig. 6 is afragmentary view of a part of the structure shown in Fig. 5, being a view taken as indicated by line 6-8 on Fig. 5. Fig. '7 is a view similar to Fig. 5, showing the parts in the opposite or reversed position so that flow from the pump is communicated to the accumulator being a view taken as indicated by line 'l-'I on Fig. 5. Fig. 8 is a fragmentary view of a part of the structure shown in Fig. '7, being a view taken as indicated by line 8-8 on Fig. '7. Fig. 9 is a detailed transverse sectional view of the structure shown in Figs. 5 and '7, being a view taken as indicated by line 99 on Fig. 5. Fig. 10 is a transverse sectional view taken as indicated by line Ill-10 on Fig. 5. Fig. 11 is a longitudinal detailed sectional view of the pilot valve involved in the control means, showing the valve positioned as it is when the jack is operating upwardly. Fig. 12 is a view similar to Fig. 11, showing the parts positioned as they are when the jack is moving downwardly. Fig. 13 is a transverse sectional view taken as indicated by line l3-i3 on Fig. 11. Fig. 14 is a transverse sectional view taken as indicated by line ll-M on Fig. 11. Fig. 15 is a detailed transverse sectional view taken as indicated by line l5--|5 on Fig. 12. Fig. 16 is an enlarged sectional view of a portion of the operating means showing the port construction involved a in such means. Fig. 17 is an enlarged view taken as indicated by line l'I-ll on Fig. 16, and Fig. 18 is a view showing the liquid make-up pump with the inlet thereto broken away to show the manner in which air is admitted to the apparatus.

The structure provided by the present invention involves, generally, a jack A that may be arranged and connected to operate a string of sucker rods or the like, a fiuid pressure generating means B involving, essentially, a constantly driven centrifugal pump, a high pressure supply means or accumulator C for the pump of means B, a main or working valve D connected with and between the elements A, B and C, operating means E for the valve D, control means F for the operating means E relating the operating means E to the jack A, a fluid reservoir G carrying a suitable supply of liquid, a reservoir I-I carrying a supply of air, a liquid make-up or feed means J receiving liquid from the reservoir G and introducing it into the apparatus, an air supply means K delivering air to the reservoir H, and

means L serving to intermittently discharge excess liquid from .the apparatus.

In accordance with the broader principles of the present invention the various essential elements hereinabove enumerated may vary widely in form, character and arrangement and in any particular adaptation of the invention such details will be governed largely by working conditions that are encountered. In the drawings 1 have shown a typical form and arrangement of elements and have shown a practical unit wherein the various elements, except for the Jack, are assembled on a frame or skid Ill to form a unit that can be readily moved and in which the parts are eflectively supported in proper cooperative relationship.

The jack A may, broadly, be any suitable hydraulic device which lends itself to operation by apparatus such as I am about to describe. In practice it is generally preferred that the jack A be a simple, hydraulic jack of the cylinder and piston type, in which case it involves a cylinder ll closed at its upper and lower ends by heads l2 and I3, and a piston 14 operating in the cylinder and carried by a rod l5 extending into the cylinder through one of the heads. In the case of a Jack for operating a string of sucker rods or the like the cylinder l I is vertically arranged over the well. For instance, it may be mounted on a frame or head construction ii at the top of the well and the rod l5 which carries the piston l4 may be a continuation of the polish rod I] which may be coupled to and form a continuation of a string of sucker rods operating a suitable pump located in a well and may extend through suitable packing glands or stufllng boxes I! provided in the head construction [6.

In thetypical case illustrated a liquid connection H is provided at the lower end portion of the cylinder H and serves to handle liquid flowing to and from the cylinder. Fluid or liquid introduced through the connection H will act under the piston H to force the piston up in the cylinder I I, whereas the weight of the piston, sucker rod and other connected parts serves to move the piston down and displace the liquid during the down stroke.

The fluid pressure generating means involves, primarily, a pump i9, preferably a centrifugal pump and a suitable drive or operating means for the pump. In the case illustrated I have shown a suitably housed internal combustion engine or prime mover 20 for driving the pump l9 and I show a belt drive 2| between the engine shaft 22 and the pump shaft 23.

The high pressure supply means or accumulator C operates to handle a supply of liquid and a body of air which acts as an air cushion, the liquid and air bein confined so that the liquid is available to feed the intake of the pump l9 while the air is under pressure and acts on the liquid so that the pump is fed under pressure. The preferred form of accumulator C, as shown in the drawings, involves a primary vessel or surge tank 24 and a secondary vessel or air tank 25. The upper end portions of the tanks 24 and 25 are connected by a top connection or duct 26 while a supply pipe 21 connects with the bottom of the surge tank and extends to the main valve D, being connected to the valve D through a suitable control valve 28. In practice the tanks 24 and 25 may vary widely in form, shape and arrangement and therefore the particular arrangement illustrated in the drawin s is considered merely as typical and for purpose of example.

The surge tank is shown as a horizontally disposed cylindrical tank closed at its ends and it serves, primarily, to handle liquid discharged from the jack A as the piston of the jack moves down, and to make such liquid available to feed or supply the pump l9 as the piston of the jack moves up. The fluid connection 21 and the valve D handle this flow of liquid to and from the tank 24 and it will be understood that the tank is made sufficiently large to adequately handle the necessary supply of liquid. The surge tank, in addition to handling liquid, as above described, accommodates a body of air above the liquid which air is in communication through the top connection 26 with that carried in tank 25.

The air tank 25 is provided primarily as a carrier for air under pressure. However, during normal operation of the apparatus a small quantity liquid will gradually accumulate in the bottom of tank 25 by reason of having reached the tank through connection 26. I provide 24 the pressure of air above the liquid intank 24 and in tank 25 increases until the liquid covers the lower end of the down spout 29, whereupon a further. rise in level of liquid in tank 24 causes an increased pressure to develop on the air in tank 24,"with the result that liquid is forced up throughout the down spout and if there is an excess of liquid present it will be forced out through the connection 26 and into tank 25 to accumulate in the bottom of tank 25.

The means L is provided for discharging excess liquid from the bottom of tank 25. The means L may be any suitable form of liquid discharge control. For instance as shown in the drawings, a drain pipe 30 may extend from the bottom of tank 25 to the reservoir G and may carry 9. diaphragm control valve 3|. The diaphragm control valve 3| may be under control of a float valve 32 through a suitable connection 33 and the float valve 32 may be so located that when a predetermined liquid level develops in tank 25 valve 32 operates causing operation of valve 3| so that liquid is drained out of tank 25 into reservoir G.

The main or working valve D is shown in detail in Figs. 5 to 10, inclusive. In its preferred form this valve is of the piston type or is a slide valve and as shown in the drawings it involves, generally, a cylinder 34 which is preferably vertically disposed and two spaced valve heads 35 and 36 carried on a stem 31 and operating in the cylinder 34. In the particular case illustrated the cylinder 34 is vertically disposed and it is provided with longitudinally spaced ports with which the valve heads 35 and 36 cooperate. The

cylinder has a lower end port 38 which communicates with a manifold 39 on the exterior of the cylinder, which manifold in turn is connected with the intake line 40 extending to the pump 9. An upper end port 4| is provided in the cylinder 34 and is also in communication with the manifold 39 to be in communication with the pump inlet line 46. Between the upper and lower ports 4| and 38 the cylinder has a port 42 communicating with a manifold 43 connected with the pipe 21 that extends to the lower end of the surge tank 24. Further, between ports 4| and 38 and above port 42 there is a port 44 communicatin with a manifold 45 which connects to the discharge line 46 from the pump I9. Further, between the ports 4| and 38 and above the port 44 to be between port 44 and port 4| there is a port 41 which communicates with a manifold 48 connected with a line 49 that extends to the connection II at the lower end of the jack cylinder The valve heads 35 and 36 are carried by the stem 31 so that they are spaced apart longitudinally of the cylinder 34 and so that when the valve is in the up position, as shown in Fig. 5, the head 35 separates ports 4| and 41 while head 36 separates-ports 42 and 44, ports 44 and 41 being in communication since they occur between the heads. When the valve is in the down position, as shown in Fig. 7 head 35 is located to separate ports 44 and 41 and head 36 is located to separate ports 38 and 42 while ports 42 and 44 are in communication since they occur between the heads.

Through the system of ports and the relationship of the valve heads to the ports above described the main control valve is shiftable between what I will term an up position where it connects the suction of the pump IS with the accumulator through ports 42 and 38 while the discharge from the pump is connected with the jack through ports 44 and 41, and a down position where it connects the discharge of the pump with the accumulator through ports 44 and 42, while the jack is connected with the suction of the pump through ports 4| and 41. During delivery of liquid through the valve D to the jack the piston I4 of the jack is forced upwardly in the cylinder while the intake of the pump is supplied with liquid under the pressure present in the accumulator C. While the piston I4 of the jack is moving down liquid from the cylinder ll of the jack is delivered to the suction of the pump and the liquid delivered by the pump is supplied to the accumulator where the cushion of air develops the desired pressure. It is to be understood that the air in the accumulator can be initially put under a suitable pressure so that the system just referred to is, in effect, a loaded or charged system operating under a high pressure. For example, in practice it may be desirable to put an initial pressure on the air in the accumulator suflicient so that the liquid in the system is under enough pressure by reason of the air in the accumulator to effect full operation of the jack proper, and the string of sucker rods connected thereto, plus about one half the load of the column of fluid being handled bythe pump attached to the sucker. rod.

The operating means E provided to work or operate the main valve between the two positions just described may be any suitable mechanism or device that will effect the necessary relative movement between the valve cylinder and the valve heads. In practice I prefer to employ a simple cylinder and piston mechanism for this purpose, in which case the rod 31 which connects the valve heads 35 and 36 may be extended out of the cylinder through one of its ends or heads through a suitable packing means 50 to a point where it can be connected to a rod 5| carrying a piston 52 operating in a cylinder 53 located above and in alignment with the cylinder 34. In the particular construction illustrated the cylinder 53 is mounted on the head 55 of cylinder 34 through which the stem 31 extends. A cylindrical cage 56 extends from the head 55 to support the cylinder 53. The cage 56 has side openings 51, and a coupler 58 is provided to connect stem 37 with stem 5|. The coupler 58 has projecting arms 59 which extend laterally from the stem 5| to cooperate with stops 59 provided in the cage 56 as a stop means for the combined mechanism formed by the connected valve D and means E. The stops may be rings carried in the cage 56.

The cylinder 53 oftmeans E is provided at each end with a main port 60 and each port 60 communicates with a manifold 6| at the exterior of the cylinder. Adjacent each port 66 and spaced therefrom toward the end of the cylinder 53 there is a cushioning port 62 which is a small port which allows for gradual escape of fluid trapped when the piston 52 passes port 66. A supply line 63 handling operating fluid to and from the control means F connects to the manifold of t1 3 upper port 60 while a supply line 64 handling operating fluid to and from the means F connects to the manifold of the lower port 60.

The control means F includes, primarily, a device that I will refer to as a pilot valve and suitable connections between the pilot valve and the other elements of the device. The pilot valve is a piston valve involving, generally, an elongate cylindrical body 65 and a stem 66 extending through the body and carrying valve heads 61 and 68 which cooperate with ports in the valve body. Operating fluid is maintained under pressure in the middle portion of the valve body being delivered to the valve body through a supply pipe 69 connected to one side of the pump 19, preferably the discharge side.

Liquid is admitted to the valve body from the line 69 through a central inlet port 10. Outlet ports H and 12 are provided in the valve body in either direction from the port '10, the port ll being connected with a manifold 13 to which line 63 is connected and the port 12 being connected with a manifold 14 to which line 64 is connected. A port 15 longitudinally spaced from port H connects manifold 13 with the interior of the valve body and an exhaust port 16 located between ports II and 15 connects the interior of the body with a drain line ll. A port 78 longitudinally removed from port 12 connects manifold 14 with the interior of the body and a port 19 located between ports 12 and 18 connects the interior of the body with a drain line 86. The drain lines 11 and B are under control of valves Il and 80 respectively and they connect together or to a drainage system which extends to the liquid reservoir G.

The valve heads 61 and 68 are carried on the stem 66 so that when the stem is to the right, as shown in Fig. 11, the head 6! closes port if cutting off communication between ports Hi and H but allowing free communication between ports 15 and 16, with the result that liquid is free to drain from line 63 through the valve to the drain line 71 where the rate of flow may be controlled by the valve Tl. At the same time head 68 closes port 19 so there is no drainage into line 86 but rather port is in communication with port 12 so that fluid under pressure from line 69 passes to and through line 64. With liquid allowed to drain from line 63 and being supplied under pressure to line 64 piston 53 of means E is subjected to pressure which causes it to move up until it reaches the upper end of cylinder 53. The speed at which the piston travels up is controlled by the valve 11 When the stem 66 is at the left, as shown in Fig. 12, the general relationship just described is reversed and line 64 is connected with drain 80 while line 63 is connected with the supply line 69 with the result that pressure is applied above piston 52 causing it to move down until it reaches the lower end of cylinder 53. The speed at which the piston travels down is controlled by the valve 80.

The control means F further includes parts and connections to effect shifting of the stem 66 between the two positions just described. An extension 85 of the stem 66 forms a ram which enters and operates in a cylinder 86 at the lefthand end of the valve body 65 and a line 81 from the suction of pump I9 is connected with cylinder 86. A head 88 011 the end of stem 66 operates in the end portion of the valve body 65 so that a catch chamber 89 is formed to catch liquid leaking from cylinder 86 and it forms an end wall in the body opening with which port communicates. A drain line 90 connects the chamber 89 with the drainage system that returns liquid to the reservoir G.

At the other end of the valve body 65 an exension 9| of the stem 66 forms a ram operating in a. cylinder 92 and a line 93 connects cylinder 92 with the upper end portion of the cylinder ll of the pump jack. A port 95 is provided in the valve body 65 between the cylinder 92 and the port 18 and is connected with the lower end portion of the cylinder of the pump jack by line 96. A valve head 91 on the stem 66 cooperates with port 95 to extend over and cover it when the stem is to the right, as shown in Fig. 11, and to uncover it when the stem is to the left, as shown in Fig. 12. A chamber I60 occurs between the ram 9i and the valve head 91 and a drain line H connects with chamber I00 so that any liquid leaking into it is drained into the drainage system which connects with reservoir G.

With the parts and connections just described when the piston M of the pump jack is below the point where line 96 connects into cylinder H, lines 93 and 96 are both under atmospheric pressure, since atmospheric pressure is admitted to cylinder H above the piston I4 through vents H0 at theupper end of cylinder il. When this condition prevails the pressure that is on the pump suction, being the pressure exerted by reason of the pressure maintained or always present in the accumulator, acts on the ram 86 to move the stem 66 to the right, as shown in Fig. 11. When the piston It starts to move up in cylinder H and after it has passed the point where line 96 connects to cylinder H, fluid pressure from the discharge side of the pump is is admitted through the cylinder of the pump jack to the line 96 but, as shown in Fig. 11, this pressure has no action on the pilot valve since the valve head 9'! covers port 95. When the piston 14 is moved to the upper end of the cylinder H and has moved past the point where line 93 connects into cylinder H, the high pressure fluid in cylinder I i beneath piston M is admitted through the line 93 to ram 9|. Since this pressure is greater than that on the suction side of the system, which suction pressure is communicated. through line 87, the ram 9| causes the stem 66 to be moved to the left and as soon as the valve head 97 uncovers port 95 the pressure admitted through line 96 acts on valve head 91 further urging it to the left and this pressure will remain on the valve head 91 and hold the stem 66 latched to the left until the piston M has returned to the lower end of the stroke to uncover the point where line 96 connects into cylinder H.

In the operation of a system such as I have described there is, in practice, always some leakage of liquid and conditions vary due to change in temperatures, etc. and therefore I provide the means J, which is a fluid make-up or feed pump, to deliver a small quantity of liquid from reservoir G into the system during normal operation thereof. In practice I preferably provide a small, positive pump H5 operated by the prime mover 20, as through a belt drive H6. The pump is supplied with liquid from the reservoir through a supply line H! and delivers liquid through a suitable check valve H8 and delivery line H9 which line is shown connected into the surge tank of the accumulator.

In practice it is also desirable to maintain a substantially constant quantity of air in the apparatus and since I have provided the means L which serves to periodically empty a quantity of liquid from tank 25 it is desirable to provide the make-up air quickly and in a quantity so that there is not a period when the system is without adequate air. For this purpose I provide the air reservoir H which may be a tank that the tank H with the air tank'25 by a line I20 and I provide a suitable pressure regulator 'I2I in the line I20 so that when the pressure of air in tank 25 drops below a predetermined value the regulator opens and allows air from tank H to flow into tank-25. The means H will ordinarily deliver air into the tank 25 when the pressure is minimum or when the tank 24 has been emptied of liquid a suflicient amount to raise the piston I4 to the top of the cylinder II.

The means K supplies air to the it may involve a small air compressor I30 driven by the prime mover of means B as by a belt drive I3I. I have shown the air pump I30 connected with 'the tank H by a line I40 equipped with a pressure regulating valve I which determines the pressure allowed to build up in tank H.

In practice I supplement the construction just described by a bleeding means which operates to normally bleed a small amount of air into the system. For instance, in Fig. 18 of the drawings I show the inlet portion of the line II! which admits liquid to the pump II5 provided with a small air inlet opening I5I so that normally as the apparatus operates a small amount of air is drawn in with the liquid passing through line I". The air inlet opening I5I is proportioned so tank H and first mentioned connection is not supplying presthat it normally admits a minimum requirement of auxiliary air or make-up air into the system and the pump I is operated so that it makes up the additional amountof required air plus a small excess which may be allowed to escape by means of the regulator 'I4I. Through this arrangement a very small air pump is all that is required to eifectively maintain the proper air supply in the system.

From the foregoing descriptionit will be apparent that the system is initially supplied with a proper amount of liquid and the accumulator is put under pressure, that is, the air in the accumulator is put under the desired or proper pressure. As the mechanism operates the control means F, being coupled with the pump jack by the lines 93 and 96 acts in direct response to the position of the piston I4 of the pump jack in the cylinder II so that the pilot valve mechanism of means F reverses as the piston I4 reaches the ends of its stroke. Reversal of the pilot valve of means F eflects reversal of the pressure conditions on means E with the result that when the pilot valve reverses means E reverses and in so doing it reverses the valve D. The reversal of valve D or the shifting of valve D between the positions shown in Figs. 5 and "1 changes the direction of operation of the pump jack while allowing the pump I9 of means B to operate constantly and so that as the pump jack moves down the pump D builds up pressure in the accumulator which is used on the following up stroke, at which time it is applied to the intake of the pump I9.

The jack A, and the operating means E are operated by the working pressure from the accumulator means C and the pump B, and the control means F or the pilot valve is operated by the pressures from the jack A. Liquid used to operate the pilot valve is delivered back to the reservoir through a suitable connection or line I50 which connects the top of the jack with the reservoir G. The pressure in the system will vary, for instance, it will be higher as the piston I4 of the jack progresses down, and lower as the piston is going up. Therefore, whenever the pressure in the accumulator becomes through loss :of air,"lower than the minimum requirement, then'the means H will charge it quickly to the minimum requirement only; The maximum requirement will be attained when the liquid is moved from thejack to the accumulator, whereupon any excess liquid is transferred from tank 24 totank 25 from which is it dumped into the reservoir G by the means L. 1

Having described only a typical preferred form and application of my invention, I do not wish to be limited or restricted to the specific details herein set forth, but wish to reserve to myself any variations or modifications that may appear to those skilled in the art, and fall within the scope of the following claims.

Having described my invention, I claim:

1. In combination, a pump having an inlet and sure to operate the valve.

2.. In combination, a pump having an inlet and an outlet, a jack including a cylinder and a piston operating in the cylinder, means connecting the pump and jack intermittently directing flow from the outlet of the pump to the jack, and a control for said means including a valve, a fluid connection between the valve and jack controlled by the action of the piston of the jack and communicating pressure to the'valve to operate it, and a fluid connection between thevalve and the inlet of the pump supplying fluid to the valve to operate it when the first mentioned connection is not supplying pressure to operate the valve, the first mentioned connection including pressure communicating lines from each end portion of the cylinder to the valve.

3. In combination, a pump having an inlet and an outlet, a jack including a cylinder and a. piston operating in the cylinder, means connecting the pump and jack intermittently directing flow from the outlet of the pump to the jack and including a fluid pressure actuated operating means, and a control for said operating means including a pilot valve controlling operating pressure for the operating means, a fluid connection between the valve and jack controlled by the action of the jack and communicating pressure to the valve to operate it, and a fluid connection between the valve and the inlet of the pump supplying fluid to the valve to operate it when the first mentioned connection is not supplying pressure to operate the valve, the first mentioned connection including a pressure communicating line connected to the cylinder and open to pressure from the cylinder only when the piston is at one end of its stroke and connected to the valve so pressure therefrom operates the valve and a pressure communicating line connected to the cylinder to be open to pressure from the cylinder except when the piston is at the other end of its stroke and connected to the valve so pressure therefrom holds the valve operated after it has been operated by pressure from the first mentioned line until the piston reaches the said other end of its stroke.

4. In combination, a pump having an inlet and an outlet, a jack including a vertically disposed cylinder and a piston operating in the cylinder, means connecting the pump and jack intermittently directing flow from the outlet of the pump to the jack and including a fluid pressure operating means, and a control for said operating means including a pilot valve controlling operating pressure for the operating means, a fluid connection between the valve and jack controlled by the action of the jack and communicating pressure to the valve to operate it, and a fluid connection between the valve and the inlet of the pump supplying fluid to the valve normally tending to operate it when the first mentioned connection is not supplying pressure to operate the valve, the first mentioned connection including a pressure communicatin line connected to the cylinder and open to pressure from the cylinder only when the piston is at the upper end of its stroke and connected to the valve so pressure therefrom operates the valve and a pressure communicating line connected to the cylinder to be open to pressure from the cylinder except when the piston is at the lower end of its stroke and connected to the valve so pressure therefrom holds the valve operated after it has been operated by pressure from the first mentioned line until the piston reaches the said lower end of its stroke.

5. In combination, a pump having an inlet and an outlet, a jack including a cylinder and a piston operating in the cylinder, means connecting the pump and jack intermittently directing flow from the outlet of the pump to the jack and including a fluid pressure actuated operating means, and a control for said operating means including a pilot valve controlling operating pressure for the operating means, a fluid connection between the valve and jack controlled I by the action of the jack and communicating pressure to the valve to operate it, and a fluid connection between the valve and the inlet of the pump supplying fluid to the valve to operate it when the first mentioned connection is not supplying pressure to operate the valve, the first mentioned connection including a pressure communicating line connected to the cylinder and open to pressure from the cylinder only when the piston is at one end of its stroke and connected to the valve so pressure therefrom operates the valve and a pressure communicating line connected to the cylinder to be open to pressure from the cylinder except when the piston is at the other end of its stroke and connected to the valve so pressure therefrom holds the valve operated after it has been operated by pressure from the first mentioned line until the piston reaches the said other end of its stroke, the pilot valve including a shiftable valve element and a ram in connection with said element operated by pressure from the first mentioned line and a head connected with the ram and operated by the pressure from the other line.

6. In combination, a pump having an inlet and an outlet, a jack including a cylinder and a piston operating in the cylinder, means connecting the pump and jack intermittently directing flow from the outlet of the pump to the jack and including a fluid pressure actuated operating means, and a control for said operating means including a pilot valve controlling operating pressure for the operating means, a fluid connection between the valve and jack controlled by the action of the jack and communicating pressure 12 to the valve to operate it, and a fluid connection between the valve and the inlet of the pump supplying fluid to the valve normally tending to operate it when the first mentioned connection is not supplying pressure to operate the valve, the first mentioned connection including a pressure communicating line connected to the cylinder and open to pressure from the cylinder only when the piston is at one end of its stroke and connected to the valve so pressure therefrom operates the valve and a pressure communicating line connected to the cylinder to be open to pressure from the cylinder except when the piston is at the other end of its stroke and connected to the valve so pressure therefrom holds the valve operated after it has been operated by pressure from the first mentioned line until the piston reaches the said other end of its stroke, the pilot valve including a body with fluid handling ports, and a shiftable element operating in the body having heads controlling the ports, a ram at one end receiving pressure from the pump inlet, a ram at the other end receiving pressure from the first mentioned line and a head receiving pressure from the other line.

7. In combination, a pump having an inlet and an outlet, a jack, a pressure accumulator, means connecting the pump, the accumulator and jack intermittently directing flow from the outlet of the pump to the jack and to'the accumulator, the accumulator being in communication with the inlet of the pump when the outlet is delivering fluid to the jack and including a surge tank handling liquid from and delivering it to the pump, an air tank, and a connection between the tanks, and a control for said means including a valve, a fluid connection between the valve and jack controlled by the action of the jack and communicating pressure to the valve to operat it, and a fluid connection between the valve and the inlet of the pump supplying fluid to the valve to operate it when the first mentioned connection is not supplying pressure to operate the valve.

8. In combination, a pump having an inlet and an outlet, a jack, a pressure accumulator, means connecting the pump, the accumulator and jack intermittently directing flow from the outlet of the pump to the jack and to the accumulator, the accumulator being in communication with the inlet of the pump when the outlet is delivering fluid to the jack and including a surge tank handling liquid from and delivering it to the pump, an air tank, a connection between the tanks, and means acting to drain liquid from the air tank upon a predetermined quantity thereof accumulating therein, and a control for the first mentioned means including a pilot valve, a fluid connection between the pilot valve and jack controlled by the action of the jack and communicating pressure to the pilot valve to operate it, and a fluid connection between the pilot valve and the inlet of the pump supplying fluid to the pilot valve to operate it when the first mentioned connection is not supplying pressure to operate th pilot valve.

9. In combination, a pump having an inlet and an outlet, 9. jack, 9. pressure accumulator, means connecting the pump, the accumulator and jack intermittently directing flow from the outlet of the pump to the jack and to the accumulator, the accumulator being in communication with the inlet of the pump when the outlet is delivering fluid to the jack and including a surge tank handling liquid from and delivering 13 it to the pump. an air tank, a connection between the tanks, and means acting to drain liquid from the air tank upon a predetermined quantity thereof accumulating therein and a control for the first mentioned means including a pilot valve, a fluid connection between the pilot valve and jack controlled by the action of the jack and communicating pressure to the pilot valve to operate it, a fluid connection between the pilot valve and the inlet of the pump supplying fluid to the pilot valve to operate it when the first mentioned connection is not supplying pressure to operate the pilot valve, and means operating to add air to the accumulator.

10. In combination, a pump having an inlet and an outlet, a jack, a pressure accumulator, means connecting the pump, the accumulator and jack intermittently directing flow from the outlet of the pump to the jack and to the accumulator, the accumulator being in communication with the inlet of the pump when the outlet is delivering fluid to the jack and including a surge tank handling liquid from and delivering it to the pump, an air tank, a connection between the tanks, and means acting to drain liquid from the air tank upon a predetermined quantity thereof accumulating therein, and a control for the first mentioned means including a pilot valve, a fluid connection between the pilot valve and jack controlled by the action of the jack and communicating pressure to the pilot valve to operate it, a fluid connection between the pilot valve and the inlet of the pump supplying fluid to the pilot valve to operate it when the first mentioned connection is not supplying pressure to operate the pilot valve, and means operating to make up escaping liquid.

11. In combination, a pump having an inlet and an outlet, 9. jack, a pressure accumulator, means connecting the pump, the accumulator and jack intermittently directing flow from the outlet of the pump to the jack and to the accumulator, the accumulator being in communication with the inlet of the pump when the outlet is delivering fluid to the Jack and including a surge tank handling liquid from and delivering it to the pump, an air tank, a connection between the tanks, and means acting to drain liquid from the air tank upon a predetermined quantity thereof accumulating therein, and a control for the first mentioned means including a pilot valve, a fluid connection between the pilot valve and jack controlled by the action of the jack and communicating pressure to the pilot valve to valve and the inlet oithe pump'supplying fluid operate it, a fluid connection between the pilot is 14 to the pilot valve to operate it mentioned connection is not supplyin pressure to operate the pilot valve, and means operating to add air to the accumulator, and means operating to make up escaping liquid.

12. In combination, a pump having an inlet and an outlet, a jack, a pressure accumulator, means connecting the pump, the accumulator and jack intermittently directing flow from the outlet of the pump to the jack and to the accumulator, the accumulator being in communication with the inlet of the pump when the outlet is delivering fluid to the jack, and a control for said means including a valve, a fluid connection between the valve and jack controlled by the action of the jack and communicating pressure to the valve to operate it, a fluid connection between the valve and the inlet of the pump supplying fluid to the valve to operate it when the first mentioned connection is not supplying pressure to operate the valve, means operating to add air to the accumulator, and means operating to make up escaping liquid.

13. In combination, a pump having an inlet and an outlet, a jack, a pressure accumulator, means connecting the pump and jack intermittently directing flow from the outlet of the pump to the jack and to the accumulator including a main valve alternately connecting the inlet of the pump with the Jack and accumulator and alternately connecting the outlet of the pump with the Jack and the accumulator, and a control for said means including a valve, a fluid connection between the valve and Jack controlled by the action of the jack and communicating pressure to the valve to operate it, and a fluid connection between the valve and the inlet of the pump supplying fluid to the valve to operate it when the flrst mentioned connection is not supplying pressure to operate the valve.

HERBERT HARVEY.

I REFERENCES CITED The following references are of record in flle of this patent:

UNITED STATES- PATENTS Number Name Date 1,178,111 Sundh Apr. 4, 1910 1,879,262 Hubbard Bept. 27, 1932 2,157,219 Salentine May 9, 1939 2,287,709 Ringman June 23, 1942 2,325,138 Kyle et al. July 27, 1943 2,347,302 Twyman Apr. 25, 1944 2,390,124 Ross Dec. 4, 1945 2,414,919 Ross an. as, 1017 when the the 

